Programmable amplitude compensation circuit

Abstract

According to one exemplary embodiment, an amplitude compensation circuit includes a first composite programmable buffer for receiving a first input signal with a first input amplitude. The amplitude compensation circuit further includes a second composite programmable buffer for receiving a second input signal with a second input amplitude. The amplitude compensation circuit also includes a feedback circuit coupled to respective outputs of the first and second composite programmable buffers. According to this embodiment, the feedback circuit compares a first output amplitude of the first composite programmable buffer with a reference voltage and a second output amplitude of the second composite programmable buffer with the reference voltage and provides first and second control signals for adjusting the respective gains of the first and second composite programmable buffers so as to reduce respective differences between the first and second output amplitudes and the reference voltage.

1. An amplitude compensation circuit comprising:
 a composite programmable buffer for receiving an input signal with an input amplitude; 
 a feedback circuit driven by an output of said composite programmable buffer; 
 said feedback circuit comparing an output amplitude of an output of said composite programmable buffer with a reference amplitude; 
 said feedback circuit producing a control signal for adjusting a gain of said composite programmable buffer so as to vary said output amplitude relative to said input amplitude. 
 
   
   
     2. The amplitude compensation circuit of  claim 1 , wherein said control signal adjusts said gain by changing a conductance of said composite programmable buffer. 
   
   
     3. The amplitude compensation circuit of  claim 1 , wherein said composite programmable buffer comprises a plurality of programmable buffers, wherein each of said plurality of programmable buffers is controlled by said control signal. 
   
   
     4. The amplitude compensation circuit of  claim 3 , wherein said composite programmable buffer further comprises a constant conductance buffer coupled in parallel with each of said plurality of programmable buffers. 
   
   
     5. The amplitude compensation circuit of  claim 3 , wherein said control signal causes each of said plurality of programmable buffers to be either ON or OFF so as to adjust said gain of said composite programmable buffer. 
   
   
     6. A composite programmable buffer comprising:
 at least one programmable buffer; 
 a feedback circuit comparing an output amplitude of an output of said composite programmable buffer with a reference amplitude; 
 said feedback circuit producing a control signal for causing said at least one programmable buffer to be either ON or OFF so as to vary said output amplitude. 
 
   
   
     7. The composite programmable buffer of  claim 6 , wherein said control signal varies a gain of said composite programmable buffer. 
   
   
     8. The composite programmable buffer of  claim 6 , wherein said at least one programmable buffer is coupled in parallel to a constant conductance buffer. 
   
   
     9. An amplitude compensation circuit comprising:
 a composite programmable buffer for receiving an input signal with an input amplitude, said composite programmable buffer comprising at least one programmable buffer; 
 a feedback circuit comparing an output amplitude of an output of said composite programmable buffer with a reference amplitude; 
 said feedback circuit producing a control signal for causing said at least one programmable buffer to be either ON or OFF so as to vary said output amplitude. 
 
   
   
     10. The amplitude compensation circuit of  claim 9 , wherein a conductance of said composite programmable buffer is varied when said control signal causes said at least one programmable buffer to be either ON or OFF. 
   
   
     11. The amplitude compensation circuit of  claim 9 , wherein said composite programmable buffer further comprises a constant conductance buffer coupled in parallel with said at least one programmable buffer. 
   
   
     12. An amplitude compensation circuit comprising:
 a composite programmable buffer for receiving an input signal with an input amplitude; 
 a feedback circuit driven by an output of said composite programmable buffer; 
 said feedback circuit comparing an output amplitude of an output of said composite programmable buffer with a reference amplitude; 
 said feedback circuit causing said output amplitude to vary relative to said input amplitude. 
 
   
   
     13. The amplitude compensation circuit of  claim 12 , wherein said feedback circuit produces a control signal to adjust a gain of said composite programmable buffer. 
   
   
     14. The amplitude compensation circuit of  claim 13 , wherein said control signal causes a change in a conductance of said composite programmable buffer. 
   
   
     15. The amplitude compensation circuit of  claim 12 , wherein said composite programmable buffer comprises a plurality of programmable buffers. 
   
   
     16. The amplitude compensation circuit of  claim 15 , wherein said composite programmable buffer further comprises a constant conductance buffer coupled in parallel with each of said plurality of programmable buffers. 
   
   
     17. The amplitude compensation circuit of  claim 12 , wherein a control signal causes each of said plurality of programmable buffers to be either ON or OFF so as to adjust a gain of said composite programmable buffer.